Lathe-chuck



2 Sheets-Sheet 1.

J. E. WILSON. Lathe Chuck.

No. 234,216. Patented Nov. 9,1880.4

2 Sheets-Sheet 2. J. B. WILSON. Lathe Chuck.

Patented Noy. 9, 1880.

rETS. PHOTO-UTHOGRAFHER WASHINGTON D c UNITED STATES PATENT OFFICE.

JAMES E. WILSON, OF BRIDGEPORT, CONNEOTIUUT.

LATH'E-CHUCK.

SPECIFICATION forming' part of Letters Patent No. 234,216, datedNovember 9, 1880.

Application filed May 12, 1879.

T all whom tt may conccrn:

` Be it known that I, JAMEs E. WILsoN, of Bridgeport, county ofFairfield, and State of Gonnecticut, have invented new and usefulImprovemeuts in Lathe-Chucks, which improven `nts are fully set forth inthe annexed specihcation and in the accompanying drawings.

The object of my invention is the construction of an improved lathe anddrill chuck of more than ordinary clamping power, arranged to beoperated without the use of keys or levers; and it consists in thearrangement, in such a Chuck, of a system of (lifferential gearing foroperatin g mechanism to cause the proper onvergent and divergentmovement of the jaws of the Chuck.

Referring to the drawings, which c'onsist of two sheets and eightfigures, Figure 1 is a view of my Chuck complete. Fig. 2 is an elevationshowing the Chuck-case and shaft in section,and other working partsconnected with the latter. Fig.3 is a side elevation of the shaft. Fig.4 isa perspective View of the case. Fig. 5 is a face View of theScroll-plate, showing the jaws thereon. Fig. 6 is a side view of one ofthe jaws. Fig. 7 is an end view or elevation of the shaft, on anenlarged scale, showing the gears in position thereon; and Fig. 8 is anend view of the shaft, also on an enlarged scale.

In the drawings, A is the shaft. b and c are gears. d is a pinion. h isa scro'll-plate. t'are jaws. B is the case. e is a sleeve-nut. n is aface-plate. D is an eccentric on the end of shaft A. o is an end ofshaft A projecting beyond eccentric D. 1" is a Collar on shaft D. t is aset-screw. o is a pin passing through gear c and into Scroll-plate h.

Like letters refer to like parts in the several figures.

The jaws of my Chuck are constructed with projections on one side, asshown, which fit into the grooves on the Scroll-plate h. Said jaws areof a width equal to that of the radial cuts in the end of case B, Fig.4, and the5T are caused to move therein to and from the center of theChuck by the revolution of the scrollplate. The otherinternally-operatin g parts of the Chuck consist of the hollow shaft A,having thereon a collar, r, an eccentric, D, and a projecting end, o, oftwo annular gears, b and c, and of a pinion, d.

The above-named parts are inserted in case B from the bottom in theorder shown in Fig. 2, with projection o on shaft A entering into thecenter hole in scroll-plate h, bringing the face of scroll-plate h upagainst the under side of the thick end in which the jaw-grooves areformed, as seen in Fig. 4. and pin v is inserted through coincidingholes in gear c and scrollplate IL, as shown. The said parts areretained iu case B by the screw-collar e, screwed into the lower end ofcase B up against the under side of collar r on shaft A.

In the periphery of the annular gear Z) is cut a notch, as shown, intowhich the end of screw t in the side of case B enters.

After having assembled the parts of the Chuck as above set forth andplaced the jaws z' in their grooves in the end of case B, with theirprojections in the grooves on the scrollplate, I secure plate n againstthe end of the Chuck, as shown in Figs. 1 and 2.

The annular ring-gears b and c are not constructed with anequalnumberofteeth in them. In this case gear b has thirty-one teeth and gearc has thirty, it being requisite for differential effects that one gearshould have more teeth than the other.

It is obvious that other combinations of differential gears than thespecific one herein shown and described might be constructed and appliedto a Chuck to serve the purposes of this invention. For instance, theannular ringgears b and c may be made with an equal number of teeth ineach, and the diiferential element be confined to pinion d, in which thenumber ofteeth working in gear b would differ from the number working ingear c, and vice Versa.

Pinion d is made with a face as wide as the combined width of the twogear-faces of gears b and c, and with teeth to conform to those on saidtwo gears.

It will be observed that when gears b and c are laid one upon the other,as in Fig. 7, a small number of the teeth thereon are in a correspondingposition, or very nearly so, and that from said position each way aroundthe Circle the relative position of the teeth of the gears b and cdiffers increasingly to a point opposite their coinciding points, wherea full tooth of gear b is shown between two of the teeth of itsoverlying gear c.

IOO

Shaft A is made with a central passage through it to receive the end ofa proper mandrel to fit the hored end of a lathe-spindle and to allow offreely passing the shank ot' a drill into the chuck between the jaws.Its eollarr is made of the diameter of the interior of the case I. Nextabove collar r on said shaft is the eccentric I), arranged to receivepinion d and to allow it to revolve t'reely thereon. Up above eccentricD is the central projection, o, which, when the parts are assembled, asin Fig. 2, becomes a stud on which the Scroll-plate h and gear c, pinnedthereto, revolve.

The operation of my chuck is as follows: The case being grasped by thehand and held While the shaft A is revolved, it will be observed thatgear I; is secured from revolving in case B by set-screw t; so whenshaft A is revolved pinion d is carried by eecentric I), on which itrevolves, around the circle dcscribed by the toothed portion of gears I)and c, and is caused to revolve on its own axis l),lccause gear b isfixed, as above mentioned. In so re- Volving, the teeth of said pinionsuccessively encounter the teeth of gear c, which stand in a slightlydiflercntial position to those of tixed gear b, and thus force the teethof gear c to a constantly-coinciding position with the tceth of gear I).This action of the parts just named causes gear c and the scroll-plateh, to which it is secured, to rcvolve on the axis thereof-- viz., theprojection o on shaft A-in the ratio of one to thirty, that being inthis case the proportion of difference between the pitch ot' the annulargears, hence requiringr thirty revolutions of the shaft A to etfect acomplete revolution of the scroll-plate lz. Thus the jaws are, h v thewell-known action of the Scroll plate thereupon, compelled to movesimultaneously in lines toward the center and grasp the drill or otherobject intended to be held by the chuck. Reversing the movement of theshaft A causes the jaws i to open. Since the act of revolving the chuckupon shaft A, and vice versa, causes the jaws to grasp the object heldby it, it is obvious that any force which tends to carry the chuckfarther around on its shaft in the same direction must cause the jawsthereof to gripe still tighter. Hcnce it is that the tendency of a drillto turn in its chuck when forced to its work will in this chuck causethe drill to be held more tightly and prevent any slip between the jawsand the shank of the drill. IIowever tightly the chuck may have beenforced upon a drill or other object, it cannot be so set beyond thepower of the hand alone, grasping the case, to reverse and open it.

I am aware that difl'crential gears have been used in hoisting-pulleysfor the purpose of securing increased lifting capacity, and I make nobroad clailn to their use for increasing the power applied; but it willbe seen that in the device above described the diferential gear is madethe medium of applying a powerful pressure to the radially-movin g jaws,whereby they can be caused to bite onto and hold the tool or articleoperated on with such force that it is practicall)v inimovable.

I clailn- 1. In a lathe` chuck, the combination of clampingiaws andscroll-plate, or its equivalent, and difl'crcntial gear, constructed asset forth, and serving as a means of forcing the said iaws with apowerful pressure upon the article to be griped, as specified.

2. The combination, with the jaw-Operating mechanism of a lathe-chuck,of the chuck-case B, the ditferential gears, consisting of the gears band a and pinion d, and shaft A, provided with the eccentric D,substantially as and for the purpose set forth.

3. The combination of shaft A, constructcd as shown. the differentialgears, consisting of the gears b and c and pinion d, Scroll-plate h,jaws case B, and nut c, substantially as and for the pnrpose set forth.

JAMES E. WILSON.

In prescnce of J osIAH H. MACY, F. W. IIURD.

